Process of treating shark skins and the like



UNITED STATES PATENT OFFlCE.

ALLEN ROGERS, OE BROOKLYN, NEW YORK, .ASSIGNOR TO OCEAN BOND CO. INC.,0]

NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PROCESS OF TREATING SHARK SKINS AND THE LIKE.

Specification of Letters Patent. Patented A r. 18, 1922.

Ho Drawing. Original application filed July 19. 1919, Serial No.311,921. Patent No. 1,395,773, dated November 1, 1921. Divided and thisapplication filed June 10, 1921. Serial No. 476,626.

To all whom it may concern:

Be it known that I, ALLEN Rooms, citizen of the United States, residingat Brooklyn, New. York, have invented certain new and usefulImprovements in Processes of Treatin Shark Skins and the like, of whicht efollo'wing is a specification.

This invention relates to the treatment of skins of sharks and the like,to remove the hard or horny coating known as dermal armor. Many attemptshave been made to remove this coating by chemical and mechanical means,but outside of the process described in my application Serial No.295,549, filed May 8, 1919, in which I describe the. treatment of theskin with hot I water while still on the animal, the efforts have beenunsuccessful and satisfactory results have not been attained.

The resent process overcomes the difiiculties eretofore experienced in.this art, and is applicable to skins that have been removed, and whichmay be 'in'a dry, fresh or salty condition. I

The present invention has for its ob e cts among'others to enable one toaccomplish the desired results in much less time and with less labor,and with a cost that is comparatively small inasmuch as the bath, whenonce prepared, may be used over and over and over again almostindefinitely before losing its efficiency.

This ap lication is a division of my ap-.

plication erial No. 311,921, filed July 19, 1919. i

In carrying out my invention, the skins are first soaked in water tobring them to a soft and natural condition. They are then placed in asaturated salt solution to which has been added one-half its volume ofcommercial hydrochloric acid, and as many pounds of salt as there. aregallons of acid.

used. In making up this bath, I have found that the followingproportions give the most satisfactory, and, possibly, the best, resultsattainable l Water 2 gallons Hydrochloric acid 1 gallon Salt 3 poundsThe addition of, more salt; I find in no wayinterferes with the results,but if less with salt, gives most satisfactory results, I

have found that other acids, such as sulphuric, nitric, acetic, lactic,and formic, will produce nearly equally satisfactory results.

In the practice of my process, the dermal armor becomes loosened inabout one and one-half hours, and may then beeasily removed over thebeam, as is the customar practice for unhairing the pelts of landanlmals.

Although the dermal armor may be readily removed when the skin is takenfrom the acid, I find it preferable to transfer the stock for a shorttime to a 10 Baum salt solution. The object of this second bath is toremove the excess acid and thus obviate the necessity of protecting thehands of the workman by rubber gloves.

While at first thought it may seem that this process would be tooexpensive for practical purposes on account of the large amount of acidrequired, it is a' fact that only a small quantity of acid is actuallyconsumed. A bath once prepared may be run almost indefinitely beforelosin its efiit ciency or becoming unfit for use. y a simle chemicaltest, the exhausted acid may e determined and the strength cheaply andquickly restored.

The salt solution used as a second bath gradually becomes acid onaccount of the liquid carried over from the first treatment. This excessof acid may be readily neutralized from time to time by addingsufiicient sodium carbonate to bring it back to its normalcondition.

I have also found that in removing the shagreen, strong solutions ofnitre-cake, salt cake, sodium acid sulphate, will also give verysatisfactory results. The best-strength to use, however, is 10 Baum.

The skins having been de armored are in a pickled condition, and maythen be handled in the same manner as are pickled skins from landanimals.

If sulphuric acid is employed in lieu of the hydrochloric acid I useonly one-half gallon to each two gallons of water likewise the sameamount of nitric or formic acid should be employed. If either acetic orlactic acid is used, I employ one gallon of each to each two gallons ofwater.

Modifications within the scope of the appended claims may be resorted towithout departing from the spirit of the invention or sacrificing any ofits advantages.

What is claimed as new is 1. A step in the method of removing the

